Roving frames are used for producing so-called rovings or coarse rovings in preparation of the spinning operation for the purpose of obtaining a fiber-type thread, for example on a ring spinning frame. The roving, which serves as the preparatory material for the spinning operation on a ring spinning frame, is usually produced from a drawing frame sliver, which is drawn on drafting rollers of the roving machine and then provided with a slight twist to allow for draft-free winding of the roving onto a bobbin. The intensity of the applied twist may only be such that, on the one hand, it is sufficient to hold the fibers together for the purposes of winding, unwinding and transporting the bobbins. On the other hand, however, this so-called protective twist must be sufficiently small with regard to the drafting on ring spinning frames such that no draft interferences are created in the course of the further processing steps. Despite the incorporated protective twist, the roving must not lose the drafting capacity thereof.
The drawing frame sliver that is used in the production of the ravings consists of so-called short-staple fibers. Preferably used for this purpose are cotton fibers or cotton and artificial fiber blends. When processing natural fibers, such as cotton in the context of a spinning process, dirt or short fibers as well as parts of fibers are separated from the drawing frame sliver and released into the environment. Airborne components of this kind and any deposits that may form because of them pose a hazard for the used machinery. The level of contamination increases, when the operating conditions change, particularly when the production speed for the making of coarse ravings is accelerated.
Modern roving frames for the production of coarse ravings perform at operating speeds that are faster by a factor that is multiple times higher in comparison to earlier machines. The high yield speeds correspondingly require that spinning frames are adapted to new circumstances.
Winding machines that are suited for threads being wound on at continuously high speeds and that do not require any change and/or reduction of the yield output during the replacement operation of a bobbin tube are known from chemical fiber manufacturing. EP 1 053 967, for example, discloses a winding machine of this kind. The winding machine includes a turret winding head that holds two winding pins. A first winding pin is in a winding position, and a second winding pin is in a doffer position. The full bobbins are removed from the winding pins, when the machine is in the doffer position, and then replaced with empty bobbin tubes. When the bobbins, which are disposed in the winding position, are full, the turret is rotated by 180° causing the winding pins to switch positions. Due to the completed turret rotation, the winding-on threads are separated from the full bobbins and taken over by the empty bobbin tubes without interrupting or reducing the yield output. The winding pins are disposed horizontally. The thread guide from which the thread changes to the traversing means is disposed at a certain distance relative to the traversing means itself. This results in a longer path that the thread must traverse from the thread guide to the extreme position of the traversing means, in contrast to the times when the traversing means is in the center position. This is why, with each movement of the traversing means, there results a certain draft. The yarns that are processed by means of the above-described winding machines are continuous polymer threads. Such types of thread typically do not generate dirt or airborne dust nor short fibers that have become separated from the sliver. In contrast, any cotton processing is associated with a great deal of dirt, dust and short fibers or broken off parts of fiber lengths. This is why cotton-processing machines are equipped with cleaning and suction means.